Shock isolation system



Feb. 13, 1968 J. o. FREDRICKSON ETAL SHOCK I SOLATION SYSTEM 2 Sheets-Sheet 1 Filed April 19, 1965 INVENTOR. JOHN D. FREDRICKSON BRUCE HANNA M ATTORNEYS 2 Sheets-Sheet 2 Feb. 13, 1968 J. D. FREDRICKSON 'ETAL SHOCK ISOLATION SYSTEM Filed April 19, 1965 N V 2 R0 o 05 TK N I'll. N R Em 0 WWW w 2 1 v A A. u 5 )k D. a U uw llll l H W J B k 3. 8 5 I m m w 2 I 2 o 7 7 United States Patent Office Patented Feb. 13, 5368 3,368,452 SHOCK ISOLATION SYSTEM John D. Fredrickson, St. Louis, Mo., and Bruce Hanna,

Littleton, Colo., assignors to Martin-Marietta Corporation, New York, N.Y., a corporation of Maryland Filed Apr. 19, 1965, Ser. No. 449,081 9 Claims. (Cl. 891.816)

This invention lies in the field of suspension or support systems for shock sensitive objects, and is more particularly directed to a missile launching system in which the missile is yieldingly supported in such manner that shock forces such as those resulting from bombardment will be resolved into vertical and horizontal components passing through the center of gravity of the missile and launch tube assembly, and will not apply upsetting moments which could seriously damage the missile.

In hardened base type installations, frequently referred to as silos, a shell of concrete or the like having a closed bottom is formed or set down into a slender deep hole in the ground, and earth is packed tightly around the exterior wall. A cover plate of steel or other suitable material is placed over the open upper end of the shell or enclosure to make a practically air tight container to house a missile. When it is desired to fire or launch the missile, the cover is removed and the missile may then rise freely from its enclosure. The latter, with its cover, takes the direct shock forces of bombardment whether they come directly from the air or through the ground, and provides basic protection for the missile.

However, in modern warfare, these forces are to great that the entire enclosure may move through substantial distances vertically or horizontally or both. If such forces and movements were applied directly to the missile they could seriously damage its structure. Consequently it has been common practice to flexibly suspend a missile in its enclosure so that it will have freedom of movement independent of the movement of the enclosure, thus reducing the shock effect of the forces applied and usually reducing the shock effect of the forces applied and usually reducing the amplitude of movement because of rapid force reversal.

A conventional arrangement for providing such support comprises a platform or base located in a horizontal position near the bottom of the enclosure, a plurality of flexible cables secured at their upper ends to the upper portion of the wall of the enclosure and hanging vertically in parallelism, and resilient means such as coil springs connecting the lower ends of the cables to the periphery of the platform. A missile, or a launch tube enclosing a missile, is mounted in vertical attitude with its lower end resting on the platform.

Vertical movement of the enclosure acts through the springs to gradually overcome the inertial of the missile and raise or lower it to some extent, and force reversal acts to return it to its original position. Lateral, or hori zontal, movement of the enclosure acts through the parallelogram arrangement of the cables and platform to exert lateral forces but with a reduction of the shock effect. However, these forces are exerted on the platform and thus are applied to the lower end of the missile, far below its center of gravity. The result is that a turning or upsetting moment with a very long moment arm is applied to the missile about its center of gravity. If the force is great enough or prolonged enough the missile or its launch tube will rotate so far that it will strike the wall of the enclosure and can readily damage the missile structure to such an extent that it will become inoperative for launch purposes.

The present invention retains all of the advantages of the conventional system and overcomes the difliculties described above. In the new arrangement a cable-suspended platform is provided to support the weight of a missile or a missile and launch tube assembly. In its presently preferred form, the platform comprises a pair of ring beams or annular frames surrounding the lower end of the assembly and vertically spaced from each other by a plurality of coil springs. The upper ring beam takes the direct gravity load of the assembly and applies it in compression through the springs to the lower ring beam. A plurality of flexible cables are attached to the upper portion of the wall of the enclosure and hang vertically and parallel to each other, and their lower ends are attached to spaced points about the periphery of the lower ring beam. The construction is symmetrical so that all vertical forces applied through the enclosure to the cables and ring beam are resolved into a single vertical component passing through the center of gravity of the assembly.

In addition, a plurality of guide members are mounted on the outer wall of the launch tube substantially in a horizontal plane passing through the center of gravity of the assembly. One guide member is provided for each of the cables and is formed with a vertical passage therethrough to slidingly receive its respective cable, thus providing for relative vertical movement of the enclosure and the assembly. The provision of these guide members alters the effective parallelogram arrangement of the cables and the platform because it restricts the lower portions of the cables to positions parallel to the lower portion of the launch tube at all times.

The movable portion of the parallelogram now extends from the guide members to the connections of the upper ends of the cables to the enclosure wall. The horizontal force component applied by the enclosure to the upper end of any cable is in turn applied to the corresponding guide member and therefore is applied to the assembly substantially at its center of gravity, with no resulting turning or rolling moment. Since the cables are spaced around the periphery the result is the same regardless of the compass direction of the applied horizontal force.

It will thus be seen that, with the novel construction and arrangement described above, any force or combination of forces applied to the enclosure will be resolved into only horizontal and vertical forces applied through the center of gravity of the assembly and will result in only horizontal and vertical movements of the assembly. With no turning or rolling moments, the assembly will at all times maintain its upright attitude parallel to the axis of the enclosure. The vertical and horizontal space made available for freedom of movement is as large as necessary for optimum results. It is recognized and accepted that catastrophic forces may be encountered which go beyond the scope of protection afforded by this arrangement but it is not practical to guard against such forces.

Various other advantages and features of novelty will become apparent as the description proceeds in conjunction with the accompanying drawings, in which:

FIGURE 1 is a vertical elevational view, partly in section, of a typical missile launching installation incorporating the features of the invention;

FIGURE 2 is a similar view in diagrammatic form 3 illustrating the construction and functions of the present invention;

FIGURE 3 is a sectional view taken on line 3-3 of FIGURE 2;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 2;

FIGURE 5 is a diagrammatic elevational view, partly in section, illustrating the operation of the conventional suspension system; and

FIGURE 6 is a fragmentary elevational view, partly in section, of a modified form of suspension means.

The general construction and operation of the conventional suspension system are illustrated in simple form in FIGURE 5. The enclosure 10 includes a generally cylindrical side wall 12 and bottom 14 and is open at the top for launching of the missile contained in launch tube 16. The center of gravity of the missile and tube assembly is at 18. A plurality of support brackets 26 are spaced around the enclosure wall near its upper end. A flexible suspension cable 22 is secured at its upper end to each bracket and is connected at its lower end by means of spring 24 to platform 26.

Under bombardment the enclosure 10 is subjected to Vertical forces 28 and horizontal forces 30. The vertical forces will increase or decrease the tension in springs 24 depending on direction. Since the suspension means are regularly spaced around the periphery and the springs are uniform, the resultant force will have a component passing vertically through the center of gravity and the assembly will rise or fall to some extent in response to force reversals and will maintain its vertical attitude.

However, a horizontal force applied to the enclosure, for instance to the left as seen in FIGURE 5, will exert a force to the left on supports 20. Through the cables and springs a similar force will be applied to platform 26 and therefore to the lower end of tube 16. This force will result in a clockwise moment 32 around center of gravity 18 and the assembly will rotate clockwise out of vertical toward wall 12, as shown in dotted lines, eventually striking it and causing damage to the control mechanism of the missile.

Turning now to FIGURE 1, there is presented a general illustration of a typical launching system installation incorporating the present invention. The enclosure includes an upper generally cylindrical section 34 open at the top and bottom, with a removable cover 36 at the top and a work room 38 used in conjunction with other facilities for checking out and adjusting various missile control mechanisms. It is constructed of concrete or other suitable material as is the lower cylindrical section 40 having a closed bottom 42. Normally these sections are sunk in the ground as shown and contacted by closely packed earth. The enclosure shown is provided at the bottom with a resilient buffer member 44.

Located within the enclosure is an enlongate vertically extending launch tube 46, within which is mounted a typical missile 48. The launch tube is formed at its lower portion with a reduced section 50 to form a shoulder 52. The shoulder rests on a heavy, strong annular structural member 54, referred to as a ring beam, which surrounds section 50, although this is not essential. A second ring beam 56 is concentric with beam 54 and is vertically spaced therefrom by a plurality of peripherally spaced compression springs 58 which yieldingly transfer the gravity load of the missile and launch tube assembly 46, 48 from the upper ring beam to the lower ring beam.

The latter has movably connected to it at spaced points around its periphery the lower ends of a plurality of flexible cables 60, the upper ends of which are movably connected to peripherally spaced support members 62 carried by the upper portion of enclosure wall 34. The cables extend vertically and parallel to each other. A plurality of guide means or members 64, one for each cable, are spaced about the periphery of the launch tube and are secured thereto at a vertical position lying substantially in a horizontal plane passing through the center of gravity of the missile and launch tube assembly. Similar guide means 94 may be provided on the periphery of ring beam 54.

As seen in FIGURE 6, each guide member is provided with a vertically extending passage 66 to freely and slidably receive the cable. FIGURE 6 also shows an alternative suspension means in the form of at least two rods 68 and 70 connected to each other by a pair of eyes 72 and 74 respectively to form a pivotal connection far enough above member 64 to prevent interference with normal vertical relative movement. The rod assembly is movably connected at its upper and lower ends to support 62 and lower ring beam 56 and functions as an elongate flexible suspension element in the same way as a cable 60.

For simplicity of illustration and explanation the construction of FIGURE 1 has been reproduced diagrammatically in FIGURE 2, Where a simple one piece enclosure 76 having a side wall 78 and bottom wall 80 is adapted to house a missile mounted within launch tube 46. Those members which are the same as members in FIGURE 1 have been given the same reference numerals. The relation of various parts in plan view is illustrated in FIGURES 3 and 4. As further illustrated in FIGURE 2, in order to prevent column buckling of the springs, retainers in the form of telescoping members 82 and 84 may be located within each spring.

As can be readily seen in FIGURE 2, cables 60, movably connected at their upper ends to supports 62 and at their lower ends to the periphery of ring beam 56, support the gravity load of the missile and launch tube assembly within the enclosure 76. In repose, they hang vertically and parallel to each other, as shown in solid lines. The vertical and horizontal loads which may be applied to the enclosure are illustrated at 86 and 88. If an upward force is applied to the enclosure it will be transmitted through cables 60 to the ring beam 56 which will rise and compress springs 58. They in turn will apply an upward yielding force to ring beam 54 and the assembly and gradually move it upward. A reversal of the force and movement of the enclosure will lower ring beam 56 and reduce the compression of the springs, and the assembly will return to its position of rest. The same sort of action in reverse will occur if the initial shock force is downward. In either event, since the cables are spaced around the periphery of the enclosure and the ring beam 56, the vertical force component will pass through the center of gravity 90 of the assembly and its vertical attitude will not be disturbed.

If a horizontal force is applied to enclosure 76, for instance to the left as seen in FIGURE 2, a similar force will be applied to supports 62. They will move to the left with the enclosure, and the inertia of the assembly will cause it to momentarily remain in its initial position. The relative movement of the parts will produce the displacement indicated in dotted lines in FIGURE 2. Since guide members 64 restrict the lower portion of each suspension element to a position parallel to and constantly spaced from the body of tube 46, these lower portions will exert no lateral or horizontal force on the assembly. The active or moving parallelogram is confined to the upper portions of the cables or suspension elements extending between supports 62 and guide members 64.

Consequently the horizontal force applied at support 62 is transmitted to a corresponding guide member 64 as indicated by arrows 92 and the sole horizontal component of the shock force passes substantially through the center of gravity of the assembly. Therefore there is no moment produced which would tend to rotate or tumble the assembly and it retains its vertically upright attitude even though it is displaced laterally. The assembly, of course, starts to move to the left but the force reversal occurs so quickly that the movement is slight and the assembly rapidly returns to its initial position of rest. The same actions occur in reverse if the initial shock force is applied in the opposite direction. Thus, the effect of horizontal shock forces is substantially the same as if the assembly were supported at the guide members without interfering with the capability of the suspension system to provide ,yielding support in a vertical direction.

While it is most effective to pass the horizontal component directly through the center of gravity of the total isolated object, the invention accomplishes its purpose if the component is in the vicinity of the center of gravity so that any turning moment will be relatively small. The same basic construction and theory of operation is equally applicable to any vertically elongated container of delicate instrumentation such as the control room for the missile. It is obvious that protection is just as necessary for the control room as for the missile that is to be launched.

It will be apparent to those skilled in the art that various changes and modifications may be made in the construction and arrangement of parts as disclosed herein without departing from the spirit of the invention, and it is intended that all such changes and modifications shall be embraced within the scope of the following claims.

We claim:

1. A shock isolating ground storage and launching system for missiles subject to bombardment forces, comprising: an elongate, generally vertically extending enclosure set into the ground and adapted to house a missile in launch attitude; a vertically extending launch tube arranged within the enclosure with freedom of movement in all directions and adapted to receive a missile in launch attitude; and support means for said launch tube and missile assembly including an upper ring beam surrounding and connected to the lower portion of said launch tube; a lower ring beam spaced below said upper ring beam; a plurality of compression springs extending between said ring beams; a plurality of support members secured to the upper end of said enclosure and spaced about its periphery; an elongate, flexible suspension element secured at its upper end to each of said support members; the lower ends of said suspension elements being secured to the outer margin of the lower ring beam; said elements, in repose, extending vertically and parallel to each other; guide means on said upper ring beam slidably receiving said elements; and guide means on said launch tube slidably receiving said elements; said last mentioned guide means being located in a horizontal plane passing substantially through the center of gravity of the missile and launch tube assembly; whereby shock forces applied to said enclosure are resolved into horizontal and vertical components passing through the center of gravity of the assembly.

2. A shock isolating ground storage and launching system for missiles, comprising: an elongate, generally vertically extending enclosure set into the ground and adapted to house a missile in launch attitude; a vertically extending launch tube arranged within the enclosure with freedom of movement in all directions and adapted to receive a missile in launch attitude; an upper ring beam surrounding and connected to the lower portion of the launch tube; a lower ring beam spaced below said upper ring beam; resilient means extending between said n'ngs urging them apart; a plurality of elongate, flexible suspension elements secured at their upper ends to spaced points around the periphery of the upper end of said enclosure and at their lower ends to spaced points around the periphery of said lower ring beam; said elements, in repose, extending vertically and parallel to each other; and guide means on said launch tube slidably receiving said elements; said guide means being located in a horizontal plane passing substantially through the center of gravity of the missile and launch tube assembly; whereby shock forces applied to said enclosure are resolved into horizontal and vertical components passing through the center of gravity of the assembly.

3. A shock isolating ground storage and launching system for missiles, comprising: an elongate, generally vertically extending enclosure set into the ground and adapted to house a missile in launch attitude; a vertically extending launch tube arranged within the enclosure with freedom of movement in all directions adapted to receive a missile in launch attitude; a ring beam surrounding and connected to the lower portion of said launch tube; a plurality of elongate, flexible suspension elements secured at their upper ends to spaced points around the periphery of the upper end of said enclosure and resiliently connected at their lower ends to said ring beam to resiliently support the weight of the missile and launch tube assembly; said elements, in repose, extending vertically and parallel to each other; and guide means through which said elements extend attached to said launch tube above said ring beam at a horizontal plane passing substantially through the-center of gravity of the assembly; whereby shock forces applied to said enclosure are resolved into horizontal and vertical components passing through the center of gravity of the assembly.

4. A shock isolating ground storage and launching system for a missile, comprising: an elongate, generally vertically extending enclosure adapted to house a missile in launch attitude; a vertically extending launch tube arranged within the enclosure with freedom of movement in all directions adapted to receive a missile in launch attitude; a plurality of elongate, flexible suspension elements secured at their upper ends to spaced points around the periphery of the upper end of said enclosure; resilient means connecting the lower ends of said elements to the lower portion of the launch tube to resiliently support the weight of the missile and launch tube assembly; said elements, in repose, extending vertically and parallel to each other; guide means on said launch tube above the lower ends of said elements slidably receiving said elements; said guide means being located in the vicinity of a horizontal plane through the center of gravity of the assembly; whereby shock forces applied to said enclosure are resolved into horizontal and vertical components passing through the center of gravity of the assembly.

5. A system as claimed in claim 4; said elements comprising flexible stranded s-teel cables.

6. A system as claimed in claim 4; said elements comprising slender, flexible metallic rods.

7. A system as claimed in claim 6; each of said rods including at least two sections having a pivotal connection located above the guide means on said launch tube.

8. A shock isolating storage and launching system for a missile, comprising: an elongate, generally vertically extending enclosure adapted to house a missile in launch attitude; a vertically extending launch tube arranged within the enclosure with freedom of movement in all directions adapted to receive a missile in launch attitude; elongate suspension elements connecting the lower portion of the launch tube to the upper portion of the enclosure and including resilient means; and guide means on said launch tube above the lower end thereof in the vicinity of a horizontal plane through the center of gravity of the missile and launch tube assembly; said suspension elements engaging said guide means to transmit thereto horizontal shock forces applied to said elements whereby the resultants of said shock forces will pass substantially through the center of gravity of said assembly.

9. A housing and shock isolation system comprising: an elongate, generally vertically extending enclosure; a slender, elongate, shock sensitive, vertically extending object arranged within the enclosure with freedom of movement in all directions; and elongate suspension elements connected at their upper ends to the upper portion of the enclosure and at their lower ends to the lower portion of said object; said elements,- in repose, extending vertically and parallel to each other; and guide means on said object above the lower end thereof in the vicinity of a horizontal plane through the center of gravity of said object; said suspension elements being connected to said guide means to transmit thereto horizontal shock forces applied to said elements whereby the resultants of said shock forces Will pass substantially through the center of gravity of sald object.

References Cited UNITED STATES PATENTS 2,418,861 4/1947 Allington 20646 8 11/1949 Bickharn 21752 7/1962 Gill 22018 X 5/1963 Andrews et a1. 891.816 1/1965 Price et a1. 89-1.816

FOREIGN PATENTS 6/ 1909 Austria.

SAMUEL W. ENGLE, Primary Examiner. 

1. A SHOCK ISOLATING GROUND STORAGE AND LAUNCHING SYSTEM FOR MISSILES SUBJECT TO BOMBARDMENT FORCES, COMPRISING: AN ELONGATE, GENERALLY VERTICALLY EXTENDING ENCLOSURE SET INTO THE GROUND AND ADAPTED TO HOUSE A MISSILE IN LAUNCH ATTITUDE; A VERTICALLY EXTENDING LAUNCH TUBE ARRANGED WITHIN THE ENCLOSURE WITH FREEDOM OF MOVEMENT IN ALL DIRECTIONS AND ADAPTED TO RECEIVE A MISSILE IN LAUNCH ATTITUDE; AND SUPPORT MEANS FOR SAID LAUNCH TUBE AND MISSILE ASSEMBLY INCLUDING AN UPPER RING BEAM SURROUNDING AND CONNECTED TO THE LOWER PORTION OF SAID LAUNCH TUBE; A LOWER RING BEAM SPACED BELOW SAID UPPER RING BEAM; A PLURALITY OF COMPRESSION SPRINGS EXTENDING BETWEEM SAID RING BEAMS; A PLURALITY OF SUPPORT MEMBERS SECURED TO THE UPPER END OF SAID ENCLOSURE AND SPACED ABOUT ITS PERIPHERY; AN ELONGATE, FLEXIBLE SUSPENSION ELEMENT SECURED AT ITS UPPER END TO EACH OF SAID SUPPORT MEMBERS; THE LOWER ENDS OF SAID SUSPENSION ELEMENTS BEING SECURED TO THE OUTER MARGIN OF THE LOWER RING BEAM; SAID ELEMENTS, IN REPOSE, EXTENDING VERTICALLY AND PARALLEL TO EACH OTHER; GUIDE MEANS ON SAID UPPER RING BEAM SLIDABLY RECEIVING SAID ELEMENTS; AND GUIDE MEANS ON SAID LAUNCH TUBE SLIDABLY RECEIVING SAID ELEMENTS; SAID LAST MENTIONED GUIDE MEANS BEING LOCATED IN A HORIZONTAL PLANE PASSING SUBSTANTIALLY THROUGH THE CENTER OF GRAVITY OF THE MISSILE AND LAUNCH TUBE ASSEMBLY; WHEREBY SHOCK FORCES APPLIED TO SAID ENCLOSURE ARE RESOLVED INTO HORIZONTAL AND VERTICAL COMPONENTS PASSING THROUGH THE CENTER OF GRAVITY OF THE ASSEMBLY. 